某有色金属企业污水处理厂污水处理工艺

对有色金属冶炼过程中产生的废水按特征因子的不同进行分质处理。其中,高浓度氨氮废水采用三级氨氮吹脱、吸收工艺进行脱氨预处理;含砷酸性废水采用三段中和-铁盐混凝法预处理;经预处理废水混合后,采用石灰法分级沉淀处理废水中重金属离子;然后根据各单位对回用水水质的不同要求,对废水进行深度处理,实现了污水处理后全部回用,污水零排放的目的。并且对污水中的氨、石膏、镍等资源进行回收利用,为企业降低了运行成本,并且防止了二次污染。     

基于发光细菌的细颗粒物(PM_(2.5))可溶性提取液综合生物效应测试方法及其应用

为科学评估PM_(2.5)对生物体综合生物效应,研究建立了利用费氏弧菌检测PM_(2.5)水溶性提取液的毒性测试方法,确立了PM_(2.5)样品提取液发光细菌毒性测试实验质量控制办法。对春节烟花爆竹燃放和沙尘污染过程的PM_(2.5)实样测试表明:烟花爆竹燃放期间的PM_(2.5)样品提取液发光抑制率值与微量金属元素等有毒有害组分浓度显著相关;沙尘污染期间的PM_(2.5)样本提取液中地壳元素浓度和发光抑制率值显著不相关。     

偏压条件下地铁工作井开挖安全及井-隧相互影响研究

武汉地铁正处于实现"主城成网、新城通线"目标的关键时期,地铁施工安全尤为重要.为研究偏压条件下地铁工作井(深基坑)开挖安全及井隧相互影响,以武汉地铁19号线5标段4号井为例,首先依托工程地质勘察资料建立三维数值模型,对深基坑变形进行了数值模拟计算与分析;然后在施工过程中对深基坑周边地表沉降、围护桩深层水平位移、内支撑轴...     

市政污泥焚烧过程中重金属迁移转化行为研究进展

焚烧已成为市政污泥处置或资源化利用的重要手段.焚烧过程会改变市政污泥中重金属的化合态和价态,从而影响其迁移转化行为.目前,国内外已对市政污泥焚烧过程中重金属的迁移转化行为开展了大量研究.梳理和归纳了市政污泥特性以及焚烧炉炉型、焚烧温度、停留时间、反应气氛和添加物等工况对重金属迁移转化行为影响的研究进展,并提出了未来仍需...     

基于土壤气中实测苯浓度的健康风险评价

以室外呼吸暴露途径为例,推导了该途径下基于土壤气中ρ(VOCs)的风险计算模型,并在北京某焦化厂苯污染区域进行应用. 结果显示,相同暴露途径下,与采用ASTM模型的理论计算值相比,基于现场土壤气中实测的ρ(苯)低至少1个数量级,基于实测土壤气中ρ(苯)所得风险值低1~2个数量级. 因此,建议对于污染范围较广、污染情况较复杂的大型VOCs污染场地,当采用ASTM模型计算的风险过于保守时,可遵循场地风险评价中分层次风险评价的思路,采用污染区域实测土壤气中ρ(VOCs)进行风险计算,确保风险计算结果更为客观、划定的修复范围更合理以节省不必要的修复资金.      

民用燃煤烟气中甲基多环芳烃的排放特征

利用全流稀释烟气采样系统,对20个煤/炉组合方式(涉及4种烟煤和1种无烟煤、块煤和蜂窝煤2种燃烧方式、3种北方地区常用的炉灶类型)的燃烧烟气进行了采样和分析,获取了多环芳烃的排放因子数据.针对具有更强“三致”作用的甲基多环芳烃(A-PAHs)的排放特征进行讨论,并与原煤的有机溶剂抽提物进行对比.结果表明,不同煤种和燃烧方式的8种A-PAHs排放因子(EFA-PAHs)差别显著,其中,烟煤在块煤与蜂窝煤两种燃烧方式下的变化范围分别为0.5~1.6mg/kg和63.9~100.1mg/kg,无烟煤以块煤与蜂窝煤燃烧的EFA-PAHs分别为0.1mg/kg和67.3mg/kg;蜂窝煤的平均EFA-PAHs比块煤高约2个数量级,说明作为洁净煤技术被推广使用的蜂窝煤燃烧方式存在“不洁净”的方面,应引起重视.对比原煤抽提物中A-PAHs的变化特征,可知燃煤烟气中的A-PAHs部分来自于煤的受热挥发,具有原煤的一些特征,但是更多的A-PAHs来自于燃烧过程中的高温裂解反应.     

Geographic variation in statolith trace elements of the Humboldt squid, Dosidicus gigas, in high seas of Eastern Pacific Ocean

We applied the solution-based inductively coupled plasma mass spectrometry to quantify trace elements in statoliths of Humboldt squid, Dosidicus gigas, collected from the high seas off Chile, Peru, and Costa Rica by Chinese squid jigging vessels during 2007–2009. All squid samples were aged and their spawning dates were back-calculated based on daily increments in statoliths. The most abundant trace elements in the whole statolith were Ca and Sr followed by other elements in the order of Fe, Mg, Zn, Ba, Cu, Mn, Ni, Al, Cr, Co, and U. Significant differences in Mn and Sr were found among samples from the three regions. Sr, Ni, Mn, and Co contributed significantly to the discrimination among the regions, with Co responsible for explaining most of the variation, followed by Ni, Mn, and Sr. Squid from the high seas off Costa Rica could be separated from those off Peru and Chile mostly due to the differences in Ni, Sr, and Co, while samples off Peru and Chile could be distinguished mainly because of differences in Mn and Co. Discriminant function analysis suggested that the overall cross-validated classification rate was 85.6 % with samples off Chile having the highest correct identification rates and samples off Costa Rica having the highest false classification rates. Significant positive relationships were found between sea surface temperature (SST) and Cr/Ca, Mn/Ca, and U/Ca, and there was a negative relationship between SST and Cu/Ca, Sr/Ca. This study suggests that the spatial difference in trace elements of statolith can be used to separate geographic populations of D. gigas and that elements having significant relationships with SST can be considered as natural indicators of ambient temperature.     

Application of an inclusion complex for determination of dithianon residues in water and fruits

A 3,3′-benzidine/β-cyclodextrin fluorescence derivative (BCDFD) was prepared and characterized by means of elemental analysis and ¹H NMR. An inclusion complex was formed between BCDFD and the pesticide dithianon based on the internal cavity of β-cyclodextrin (β-CD), and the binding constant (K_S ) of the inclusion complex was investigated. The inclusion complex could be applied for the determination of dithianon residues. Based on this, a sensitive method for the determination of dithianon was established. The linear dynamic range was from 0.63 to 12.5?mg?L^?1 with a correlation coefficient of 0.9927. The limit of detection for an aqueous solution of standard and the relative standard deviation (RSD) were 10.6?µg?L^?1 and 0.76%, respectively. The proposed method has been successfully applied for the determination of dithianon residues in water and fruit samples with satisfactory results, and recoveries in the range of 96.0–108% were obtained. The method is rapid, direct, economical, and sensitive for dithianon analysis.     

Public attitudes and perceptions to the West-to-East Pipeline Project and ecosystem management in large project construction

Ecosystem management addresses transboundary, interdisciplinary and multiparty issues from an ecosystem perspective. In this regard, public participation of ecosystem management is particularly important for achieving a successful outcome. However, public attitudes and perceptions on ecosystem management in project construction are often ignored in the developing countries. Large project construction in China is booming, for example, oil/gasoline pipelines, water diversion projects, highway networks and high-speed railway networks. These projects may have important impacts on China's economy, as well as ecosystems. The perception of local people on these projects is crucial for their safe fulfilment. In this paper, the West-to-East Pipeline Project (WEPP), a large project in China built in 2004 to transport gas from the north-west to the south-east, was used as a case study to examine public participation and perceptions on ecosystem management. Field interviews were conducted in the summer of 2005 for data collection, and logistic regression models were used for data analysis. Modelling results show that public attitudes to WEPP construction are closely related to education, occupation and place of residence. Generally, interviewees with higher education and more involvement in WEPP have a positive attitude. However, local people have a poor understanding of ecological restoration and ecosystem management. For safe implementation of WEPP, some adjunct projects are required to improve the local economy and ecosystem functions, and different economic compensation schemes should be designed for stakeholders by region. Additionally, development strategies, such as offering part-time jobs, education and training to local farmers, are necessary to change attitudes and improve awareness on ecosystem management. It is also important to strengthen public participation in the early stages of project construction.     

磷酸三(2,3-二氯丙基)酯阻燃剂对稀有鮈鲫的毒性效应

为研究新型阻燃剂磷酸三(2,3-二氯丙基)酯(TDCPP)的毒性效应,以稀有鮈鲫(Gobiocypris rarus)为实验生物,采用半静态实验方法,分别进行96 h和28 d的染毒,研究TDCPP对稀有鮈鲫的急性毒性和慢性毒性效应,并通过对稀有鮈鲫脑组织中与神经纤维的生长、发育、轴突再生等相关基因mRNA表达量的检测,初步探讨了TDCPP的神经毒性作用。结果表明：TDCPP对稀有鮈鲫的96 h-LC₅₀为2.99(2.20～3.38) mg·L^-1,根据化学物质对鱼类毒性分级标准TDCPP属于剧毒性。经0.9、1.5、2.1和2.7 mg·L^-1 TDCPP染毒28 d,与对照组相比,暴露组稀有鮈鲫肝脏及脑组织中SOD和GSH-Px的活性均受到抑制,且随着TDCPP的暴露浓度增加,其抑制作用显著增强;暴露组稀有鮈鲫脑组织中与神经纤维的生长、发育相关的微管蛋白α/β、神经丝NF-M以及关键蛋白GAP-43等基因的mRNA表达量,与对照相比均发生显著下调。可知,TDCPP暴露可以诱发稀有鮈鲫神经毒性作用。